Constant air velocity carburetor



Sept. 15, 1964 1 J. SPRANGER CONSTANT AIR VELOCITY CARBURETOR 2 Sheets-Sheet 1 Filed July 3, 1961 Sept 15, 1964 1 ,.1. SPRANGER 3,149,185

CONSTANT AIR VELOCITY CARBURETOR Filed July 3, 1961 2 Sheets-Sheet 2 /IOO Figs Fig.

Inventor'. Leonard Sprngen United States Patent CENSTf-XNT All?. *El QlTY CPWURETCUR Leonard d. Spranger, 33d St., @als Pai-lr, lll. Filed duly 3, 196i, Ser. No. 121,4@

3 Claims. (Cl. Zei-e4) This invention relates to improvements in constant air velocity carburetors, and the like. The 1h'nprovernents herein disclosed have particular reference to carburetors of the type shown in Aetters Patent of the United States, Nos. 2,52l,42l, issued September 5, 1950, and 2,552,465, issued May 8, i951, both on applications tiled by me. l wish it understood, however, that by reference to such earlier patents l do not intend to limit the protection to be alturded by the present application, and the Letters Patent to be issued thereon, except as l may so limit myself In the claims to be incorporated in any such to be issued Letters Patent; and that reference to my said earlier patents is merely by way of illustration of one embodiment of the improvements hereinafter tu be discl sed.

in each of such earlier patents i have disclosed a controlled air delivery passage provided with aligned air inlet port and mixture control port valve seats; one being the air inlet port valve seat, and the other being the mixture control valve seat; and l have also shown companion poppet valves, being inlet puppet valve and a mixture puppet valve working with respect to such seats, and aligned with each other lor valving movements in such alignment. i have also disclosed therein, liquid fuel supply valve means at the location of the mixture control port seat, and such liquid fuel supply valve means is constituted for valving operations coincidentally with the opening and closing movements of such mixture puppet valve, so that both the rate of ow of the air delivered to the mixture delivery passage, and the normal rate of supply of the liquid fuel into the air stream, are simultaneously controlled by the coordinated movements oi' such mixture puppet valve and such liquid fuel supply valve.

in that earlier type oi construction l have also disclose a common operating element connected to both such puppet valves, conveniently shown as a stem extending normal to the valve seats, and reciprocable in the direction of such stern. The inlet pop-pet valve in that earlier disclosure is connected directly to such operational stem; but the mixture puppet valve is connected to such operational stem through the medium of a lost-motion connection. Provision is made for urging such mixture puppet valve towards the inlet puppet valve as far as permitted by such lost-motion connection, such urge being produced by spring means. Normally, therefore, u1 such earlier construction a raising movement produced by a suitable control element, acting on the inlet puppet valve, also ensures a corresponding rising movement of the mixture puppet valve, .the lost-motion being normally completely taken up by the aforesaid spring urge. rThus, under normal operational conditions of that earlier construction both of the puppet valves, are moved in either the opening or the closing direction, simultaneousl' and by equal amounts of valving movement. lt is, however, possible, in that earlier construction, to purposely cause the lower or outlet puppet valve to move downwardly, against the spring urge, an amount limited by the amount of the lost-motion, or until limited by engagement of such outlet puppet valve with its outlet valve seat. Normally, the valves of that earlier construction are both held in a slight degree of opening, or non-seating, by a suitable stop element which is adjustable to the desired degree of such slight opening or cracking of the two valves.

The aforesaid suitable stop element which is adjustable, acts, in that earlier construction, on a valve control element which in turn acts directly on the inlet poppet valve,

3,l49,l35 latented Sept. 15, 1964 ICC to raise and permit lowering of such valve. Thus, such stop element also acts to limit the normal closed position of the mixture puppet valve, since that valve is, in that earlier construction, normally held iu the lost-motion position which gives positive drive ofthe lower or outlet puppet valve in the valve closing position. Thus, by suitable setting of the adjustable stop element, both of the valves me normally slightly cracked open; but it is possible, by a suitable connection, to force the mixture puppet valve into its fully closed position, without simultaneously fully closing the inlet puppet valve. ln other words, an independent special control element is provided for, at times, forcing the mixture puppet valve of that earlier construction, into its more closed or fully closed position, without at the same time, altering the position of the inlet puppet valve.

ln that earlier construction I have also shown a priming or raw gas supply valve, for use under such special conditions, as when starting the motor cold. That priming valve is, in that earlier patent, shown as having its delivery end and opening at or close to the mixture control port valve seat, such priming valve being normally closed and thus normally not delivering any liquid fuel to the air stream llowing past such outlet valve seat. However, such priming valve is so constructed that when the mixture puppet valve element is purposely forced eyond its normal cracked position it engages such priming valve, and opens such valve for delivery of raw gas into the air stream iiowing through the mixture control port, it being understood that this purposeful opening of the priming valve by a special movement of the mixture puppet valve in its closing direction, does not completely close the mixture control port, but does reduce the amount of the cracking" opening theero. lt is thus seen that in that earlier patent the special operations for control or such priming valve are produced by a special and supplemental movement of the mixture puppet valve, and not by a fully independent operational element. lt is also seen that in that earlier construction the special operational movement of the mixture puppet valve in the closing direction, for special operation of the priming valve, reduced the amount of the cracking of lthat outlet valve during such priming operation; but did not reduce the amount of cracking of the inlet puppet valve during such priming operation. Therefore, under such special priming operation oi that earlier construction, the previously existing condition of balance as between the crackings of both of the valves is destroyed at the time of and during the priming operation.

It is .an important object and feature of the present invention to provide improvements in the type of such earlier carburetor construction, such that the priming of the mixture delivered from the carburetor is accomplished independently of any change in the positions of both the inlet and the mixture puppet valves. Thereby such carburetor construction may be further moditiedin such manner as to ensure exactly equal and simultaneous opening and closing movements of both such puppet valves at all times; and thus also ensuring that, when producing the priming operation, the crackings of both the inlet and the mixture puppet valves will rei ain unchanged, and both such crackings will remain of equal or relatively unchanged size. Thus, this objective may be stated to comprise the provision of means, completely independent of the puppet valves or either of them, for actuating the priming valve, when desired, and irrespective of the pusitiou occupied by the puppet Valves during such priming operation. This independency of the priming valve operations, from those of the puppet valves, also makes it possible to bring the puppet valves to cracked positions most advantageous for idling and other motor operations, without imposing limitations on such cracking adjusti y 3 ments, due to the presence of the priming valve as a portion of the elements which impose limitations on such cracking adjustments.

In connection with the foregoing objective it is a further object to provide a priming Valve control of simple form and one which may be readily controlled from any suitable position, such as the dash-board of an automobile.

It is a further object to provide a simple form of such priming valve, and one whichmay be readily incorporated Vinto carburetorsV of the type shown in said earlier patents, by way of illustration.A

Other objects and uses of the invention will appear from a detailed description of the same, which consists in the features of construction and combinations of parts hereinafter described and claimed.

In the drawings:

FIGURE 1 shows a side elevation of a carburetor of the type shown in said earlier patents, but modied to incorporate an independent control means for the priming valve, such control means being shown in its non-priming or non-operational position;

FIGURE 2 shows a plan view corresponding to FIG- URE l;

FIGURE 3 shows a vertical longitudinal section taken on the line 3-3'of FIGURE 2, looking in the direction of the arrows;

FIGURE 4 shows a longitudinal `section through the priming valve element with its needle valve in closed position;

FIGURE 5 shows a partial vertical longitudinal section corresponding to the section of FIGURE 3, but with the poppet valves in raised or opened position, the main liquid fuel valve being correspondingly opened for supply of liquid fuel to the air stream owing through the mixture control port;

FIGURE 6 shows a plan section taken on the line 6-6 of FIGURE 3, looking downwardly in the direction of the arrows; and this figure also shows the priming valve in plan View, and unopened; n A

FIGURE 7 shows a fragmentary perspective view section through the liquid fuel supply chamber, looking in the direction of the arrows in FIGURE 3; and with the main liquid fuel supply valve closed, the mixture poppet valve being correspondingly in closed position;

FIGURE 8 shows a perspective view of the main fuel supply valve, removed from the body of the carburetor, and with such main fuel supply valve in partially opened position; and

FIGURE 9 shows a longitudinal section through the priming valve actuator which may be at a convenient location from the body of the carburetor.

In the drawings I have shown, by way of illustration,

only, the improvements of the present application as in-V corporated into a carburetor of the general construction shown in my said patent, No. 2,552,465. However, 1n

so illustrating such improvements I do not intend to limit myself to their incorporation of carburetors constructed as shown in said Letters Patent, except as I may limit myself in the claims to follow. Accordingly:

f The body of the present carburetor is formed to provide an air chamber 56 in line with a mixing chamber 51 to one side of which is ya fuel chamber 52. The walls defining these three chambers are joined to provide a unitary structure. Leading into the fuel chamber 52 is a fuel pipe 53, and opening into the air chamber 50 is an air inlet passage 54. The bottoni of the mixing chamber 51 is open for operative connection to the intake manifold (not shown)V of an internal combustion motor.

The flow of liquid fuel into the fuel chamber S2 is controlled by a valve inthe pipe 53, operated by a float 55 which is pivotally supported upon a rod 56 to swing up or down inresponse to fluctuationsA of the level of the fuel within the chamber. By such a conventional means it is such poppet valve.

i possible to keep a substantially constant level of the fuel within the fuel chamber at all times.

Between the chambers 50 and 51 there is a controlled air delivery passage 57; and the ports 5S and 59 establish communication of such passage 57 with the air chamber 50, and with the mixture delivery passage 51, respectively, when such ports are open or unvalved. Thus the port 58 is an air inlet port, and the port 59 is a mixture control port to and from such passage 57, respectively. Such ports are provided with the upwardly facing valve seats 60 and 61, respectively, the seat 6) being an inlet poppet valve seat, and the seat 61 being a mixture poppet valve seat. The poppet valves 62 and 63 control the openings 58 and 59, respectively, for which purpose such valves `are movable vertically from and towards their respective seats, and at fixed separation from each other. Conveniently, such valves are both connected to a telescoping element comprising the rod 64 extended axially through the sleeve 65; the inlet Valve 62 being connected to such sleeve, and the valve 63 being connected to such rod. The rod and sleeve are factory adjustable endwise with respect to each other, thus factory adjusting the spac# ing between the two poppet valves. In the arrangement shown, such factory adjustment may be accomplished by use of a threaded connection 66 between the rod andV sleeve elements, so that by turning the rod it can be threaded either upwardly or downwardly in the sleeve, with corresponding adjustment of the spacing between the two valves 62 and 63. Such turning of the rod is readily effected by use of a wrench applied to the flattened upper end 67 of the rod. The rod and sleeve are then locked in the adjusted relation by such means as the nut 68 threaded onto the rod and threaded into lirm engagement with the top surface of the sleeve element, a lockl nut 69 being then tightened against such nut 68. If desired, a set pin 70 may also be set through both the rod and the sleeve after they have beenthus factory adjusted, to prevent unauthorized change or tampering with the adjusted relation between the parts. It is thus understood that the adjustment of the two poppet valves with respect to each other is of the type conventionally known asa shop adjustment, being an `adjustment made at the shop of assembly, and not intended to be changed or tampered with by unauthorized persons.

' It is now noted lthat raising and lowering of either one of such poppet valves must be accompanied by an exactly corresponding and equal raising or lowering of the other If the factory ladjustment be such that the spacing between the seating surfaces of the valves is the same as the spacing between the valve seats 60 and 59, both valves will seat at the same moved position of the unit 64-65; `and raising such unit will always unseat the valves by equal amounts. Accordingly, if such Vlowering movement be stoppedshont of dead seating of one of the valves against its seat, the other valve will necessarily `also be stopped correspondingly; and when both of the seats are spaced apart exactly the same spacing as the spacing of the poppet valves from each other, the crackings of both valves will be equal. On the contrary, if the shop adjusted spacing lbetween the two poppet valves is different from the spacing between .the two seats, then the openings of the two ports will not be equal in amount. Under these conditions one or the other poppet valve may come to a dead seat while the other such valve is still cracked; or the movements of the two valves in the closing direction -may be stopped under [the condition that the crackings of the two Valves are to be ditferent in amount.

I have provided `adjust-able means for stopping the closing movements of the two valves at a pre-determined position; for example, such closing stoppage may be with one or both of the valves cracked an amount to produce idling of the internal combustion motor. Such admovably mounted on the upper end ofthe carburetor, in

position for engagement by an element of the telescoping unit 614-65 to arrest closing movement of the poppet valves at the pre-determined position. Such block is shown as provided with the slot and screw arrangement (see FIGURE 2) by which, upon loosening the screw the wedge block may be set back or forth to the desired position of adjustment, and the screw may then be locked by tightening. The slot and screw arrangement, '72, just defined, engages a flange 73 of an element presently to be described.

The up and down movements of the two-valve unit, including the two poppet valves, may be produced in convenient manner. ln the arrangement shown, the cap 74 of the carburetor housing is provided with a downwardly extending stationary sleeve 75 within which the sleeve 65 fits with an easy sliding and rotary movement lit. Such sleeve 7S is provided with a cam-shaped slot 'lo (see FIG- URE 5), and a pin or stud 'i7 screwed or otherwise connected to the sleeve 65 rides in such slot during vertical movements of the poppet valve combination. Such vcrtical poppet valve movements are produced by turning the sleeve 65 in convenient manner, as by use of the outwardly extending ann 7S. Such arm 78 is connected to a cap element 79 or which the flange 73 comprises a part, such flange being seated onto the upwmdly extending flange 89 of the carburetor cap '74. A set screw S1 when tightened secures the flange 73 to the valve sleeve 65'. The restoring movement of the arm 78 is limited by an adjustable stop pin or stud 82 set through a lug S3 extending up from the carburetor cap 74 (see PlGURE 2). By this means the movement of the poppet valve combination in closingV direction is limited at the desired position of cracking of the valves, or even with such valves fully closed, if desired.

The lower portion of the telescoping rod-sleeve unit 64-65, together with the two puppet valves is guided by a supporting tubular guide S32 connected to the lower portion of the carburetor housing Srl by the radial arms 85'. lf desired a spring Se may be included between the lower valve 59 and such flange S3, to urge rising movement of the valve unit, with correspcndinU opening of both valves. Such spring, if provided, may serve to partially or wholly counterbalance .the weight of the valve unit, and thus facilitate normal valve control operations. lt is noted, however, that such spring, when thus provided in the present embodiment, does not serve the function assigned `to it when provided in the constructions disclosed and described in said earlier patents.

The main liquid fuel valve of the carburetor is shown at 87 in various of tbe figures, especially FIGURES 3, 5 and 8, as well as FIGURE 7 in which it is shown in detail in longitudinal section. The valve embodiment shown in said figures is the same as that disclosed in said earlier patents, so detailed description of the same is not needed here. It is to be noted that when the valving elements are properly proportioned and properly adjusted for the idling condition, such valves are slightly cracked so that air and mixture may flow past the valves in sufficient but small quantity to care for the idling requirements. Furthermore, since the spring $8 of the valve element shown in its entirety and identified by the numeral S7, FIGURES 3, 5, 7 and S, urges such valve to its fully opened position, and with the upper or outer end of such valve element in contact with the tapered or conical surface of the valve 63, the liquid fuel needed for all operations is supplied by the lateral end groove 9i? which connects with the central small hole 91 with the vertical groove Sb on the outside surface of the tube 87a for supply of such fuel during the idling operations. As the valve element '63 is raised more `and more from its seat, additional valve openings 92 are uncovered to thus ensure supply of the fuel entering the unit through the holes 37C in amount proportionate to the needs of the increased quantity of air being flowed through the outlet port S.

Next attention is called 'to the provision of valve means to prime the motor, to facilitate starting thereof, especially when the motor is cold. Such a priming valve is shown in various of the figures of the present oase, notably in FIGURES 3, 4, and 9, to which attention is invited. This priming valve is completely independent of the valving elements thus far described, and thus the operations incident to priming are not disturbed or modified by the priming operations. On the contrary, in the earlier ernbodiments disclosed in said earlier patents, the priming operation is produced by a special operation of the mixture poppet valve, serving to move `the same against the priming valve, to activate such priming valve. This special operation of such mixture poppet valve changes th relationship between the amounts of cracking of the two valves; whereas by use of the presently disclosed independent priming valve, neither of the puppet valves is actuated, and each retains its original setting of its cracking condition.

The presently disclosed priininv valve, shown in FIG-- URE 4 in enlarged detail, is of substantially the same construction `as the priming valve shown in said earlier patents; and is briefly described as foil ws:l

The priming valve includes the tubular element g2, closed at its delivery end which is, however, provided with the small central needle valve orifice 93. The plunger 94 is located in said end portion of the tubular element 92, and is provided with the outwardly extending needle 95 of tapered form which extends into or through the needle opening 93. The spring 95 extending between such plunger 94 and the screw abutment 97 at the inner end of the .tubular element 92, urges the element outwardly into the full valve closed position. However, the tapered end portion 9S extends through the needle orifice far enough to be engaged by an operating element which, by forcing the needle plunger element 94 inwardly against the spring urge, serves to provide a needle opening of size proportionate to the extent of such inward forced position.

The tubular element i2 is provided with one or more lateral openings 93 behind the plunger element, for admission or liquid fuel into the space behind such plunger element; but the plunger element itself is of polygonal form, to thus provide one or more lengthwise extending passages between the external surface of such plunger element, and the interiorsurface of the tubular element 92. Thus the liquid fuel may dow endwise through such passages to the location of the needle opening.

The above described valve unit is extended through the walls of the float chamber and the controlled air delivery passage 5?, so that communication is established between the fuel in the fuel chamber at a level below the normal surface of such fuel, and the central portion of the controlled air delivery passage, Accordingly, when the needle valve is forced bacl; against the spring 96 fuel may flow by gravity from the fuel chamber S2 through the tube 92 and orifice 93, into the chamber Sl. Such flow may be by gravity alone, when no vacuum exists in the chamber 5l (as would be the case before cranking of the engine was produced by the starter). On the other hand, when a lowered pressure is produced in such chamber 5l (as would be the case when the engine rotation was produced by the starter), the partial vacuum then existing in the air delivery passage will assist in drawing fuel through the needle opening into such passage, irrespective of any special operation of the mixture poppet valve element. On the contrary, if desired, such priming operation may be produced by depression of the needle element 4- while the mixture puppet valve is in raised condition. Thus, the priming operations are made independent of the normal operations of the mixture puppet valve. For this independent priming val e operation l have shown the following provisions In alignment with the priming valve unit just described is the actuating unit. This includes the plunger element E9 (see FlGURE 9) slidably set into the tubular element it?. Irl its central portion this plunger element is reduced in size to receive the compression spring lill which has its forward end engaged with the shoulder of the plunger element, and its rear end engaged with an adjustable nut 162 by which the urge of such spring may be adjusted. The rear end of such plunger element also extends through such nut :far enough to be engaged by a drive element, such extension being legended as lr03, The forward end portion of the plunger element is of reduced size as shown at 194, such reduced size portion extending through the front end of the tubular element lili), and being urged forwardly to bring its shoulder between the reduced size forward end portion of the plunger element, land its full size portion, into engagement with the inside of the front end of the tubular element.

Drive against the projecting portion lue will shift the plunger element endwise against the spring urge, to increase the projection of the rear end portion lil3 beyond the rear end of the tubular element.

This drive unit is set through the wall of the mixture delivery passage far enough to bring the plunger end 163 close to the projecting end portion of the needle 95 of the priming valve. Under these conditions pressure exerted against the projecting end portion lil-4 will shift such plunger element towards the priming valve, with corresponding drive of the needle valve 95 inwardly, to thus open .the needle opening, fordelivery of priming liquid into the mixture delivery passage.

The drive against the end portion 164 of the plunger element may be produced in any convenient manner. in the drawings I have shown the lever element 195 pivoted to the stud 166 carried by the carburetor, such pivot being shown at t. The upper end portion of such lever aligns with the projecting end portion lud, so that pull on the lower end of the lever drives the plunger element 99 towards and against `the needle valve, as already ex-v plained. Such pull on the lower end of the lever 16S may be effected by a tension element MBS carried to the dash-board or other convenient location for manual or other operation.

The plugs 1639 and 11i? are removably inserted into openings of the fuel supply chamber 5?; at locations for convenient removal or adjustment of the main fuel valve 87, and the priming fuel valve 92, respectively.

Examination of FIGURE 3 shows the liquid level as determined by the float 55 substantially at the line 11i. It is noted that the priming valve unit 92 is substantially horizontal, and that the inlet openings 98 are below thel surface of the controlled level inthe supply chamber. Accordingly, the priming liquid delivered through such priming unit finds substantially a gravity feed to the mixture delivery passage, in addition to the syphoning effect produced by the partial vacuum existing in such passage.

I claim:

1. In a carburetor, the combination of an air inlet passage and a controlled air delivery passage, an air inlet port between said passages, a mixture delivery passage, and a mixture control port between the controlled air delivery passager-and the mixture delivery passage, inlet and mixture poppet valves `for said air inlet port and said mixture control port, respectively, said ports and said poppet valves being in vertical alignment with each other, a vertically movable stem extending through the air inlet port and through the mixture control port, means to secure both of the poppet valves to said stem at a fixed distance between said poppet valves equal to the valve seating disf tance between said air Yinlet port and the mixture control port, a liquid fuel supply oat chamber in horizontal alignment with the mixture delivery passage, means to move said stem in the direction of the Vaxial alignment of the ports for simultaneous change of the openings of both of the ports by equal amounts, a main liquid fuel supply conduit having its inlet end in communication with the float chamber and-its delivery end terminating at the location of the mixture control port and including valve means in the path of movement of the mixture poppet valve, constituted to cause opening and closing movement of the main liquid fuel supply conduit valve proportional to the opening and closing movements of the mixture poppet valve, together with a priming liquid fuel conduit having its inlet end in communication with the float chamber and its delivery end terminating in the mixture delivery passage beyond said mixture control port in the direction of mixture iiow and in horizontal alignment with the iioat chamber, valve means in said priming fuel conduit for control of the delivery of priming liquid fuel from the float chamber to the mixture delivery passage, and means independent of the puppet valves and independent of the stemconnection between sm'd puppet valves to actuate the priming liquid valve means.

2. A carburetor -as defined in claim 1, wherein ,the priming liquid fuel conduit terminates in the mixture delivery passage at a location below the mixturev control port. A

3. A carburetor yas defined in claim 1, wherein the priming mixture fuel conduit valve means comprises-a needle valve including a needle opening from the conduit into the mixture delivery passage, and a needle element movable axially of the conduit and projecting into the mixture delivery passage, 4and wherein the means Ato ac-VY tuate the priming liquid valve means independent of the poppet valves, comprises an element movable axially with respect to the needleelement of the priming fuel conduit valve means `and into actuating engagement with such needle element, together with means to move said element which is movable axially with respect -to the needle element. towards the needle element.

References Cited in the file of this patent UNITED STATES PATENTS 2,040,945 Leuschner V May 19, 1936 2,393,125 st. Cuir June 15, 1946 2,552,465 

1. IN A CARBURETOR, THE COMBINATION OF AN AIR INLET PASSAGE AND A CONTROLLED AIR DELIVERY PASSAGE, AN AIR INLET PORT BETWEEN SAID PASSAGE, AMIXTURE DELIVERY PASSAGE, AND A MIXTURE CONTROLL PORT BETWEEN THE CONTROLLED AIR DELIVERY PASSAGE AND THE MIXTURE DELIVERY PASSAGE, INLET AND MIXTURE POPPET VALUES FOR SAID AIR INLET PORT AND SAID MIXTURE CONTROL PORT, RESPECTIVELY,SAID PORTS AND SAID POPPET VALVES BEING IN VERTICAL ALIGNMENT WITH EACH OTHER, A VERTICALLY MOVABLE STEM EXTENDING THROUGH THE AIR INLET PORT AND THROUGH THE MIXTURE CONTROL PORT, MEANS TO SECURE BOTH OF THE POPPET VALUES TO SAID STEM AT A FIXED DISTANCE BETWEEN SAID POPPET VALVES EQUAL TO THE VALVE SEATING DISANCE BETWEEN SAID AIR INLET PORT AND THE MIXTURE CONTROL PORT, A LIQUID FUEL SUPPLY FOAT CHAMBER IN HORIZONTAL ALIGNMENT WITH THE MIXTURE DELIVERY PASSAGE, MEANS TO MOVE SAID STEM IN THE DIRECTION OF THE AXIAL ALIGNMENT OF THE PORTS BY EQUAL AMOUNTS, A MAIN LIIQUID FUEL SUPPLY CONDUIT HAVING ITS INLET END IN COMMUNICATION WITH THE 